The present invention relates to an information processing apparatus, an information processing method and a provision medium, and more particularly to those adapted for detecting a commercial advertisement (herein referred to as a “commercial” or a “CM”) included in a television broadcast.
When reproducing a recorded television broadcast, some users want to watch only the program itself without any commercials. In order to satisfy this desire, there are known video recorders equipped with a commercial cut function to skip commercials by fast forwarding.
A typical commercial detection algorithm employed in such a video recorder is based on the following characteristics common to most commercials. That is, a quiet section of 0.1 to 2.0 seconds is at the start and end of each commercial; image scene change points are in the quiet section; the required time of each commercial is an integral multiple of 15 seconds; and (e.g., for commercials broadcast outside of the United States) the audio multiplex mode changes from a monaural mode for programs to a stereo mode for commercials. In television broadcasts in Europe and America, black or blue frames are typically inserted between a program and a commercial. Upon confirmation of such characteristics, the relevant portion is detected as a commercial.
Therefore, according to the known commercial detection algorithms, it is impossible to detect any commercial that holds none of the above characteristics, e.g., a Japanese commercial where the audio multiplex mode is monophonic.
Another problem according to the known commercial detection algorithm is that, in case the above characteristics are included in the program, the relevant portion thereof is detected as a commercial.
Further, if any characteristic of the commercials employed in the known algorithm were changed or abolished (for example, if the required commercial time were changed to an integral multiple of 14 seconds or if the insertion of black or blue frames were abolished in Europe and America), there would arise a problem that commercials would be rendered undetectable.
In a quiet section detection method adopting the known commercial detection algorithm, a quiet section is detected by first calculating the average audio level in a certain section and, if the calculated average level is below a predetermined threshold value, regarding the relevant section as a quiet one. Consequently, the precision of such quiet section detection becomes different when the television reception is not satisfactory, i.e., if the radio field intensity is low and the S/N of the audio signal is inferior, or if the radio field intensity is not low. Under such circumstances, accurate detection of commercials may be impossible.
Moreover, according to the known commercial detection algorithms, the required commercial time is clocked by counting the number of frames on the basis of approximately 30 frames per second. However, since an error of several frames is often caused in an actual broadcast, a margin of error is provided in the threshold value for decision of the required time. Consequently, erroneous detection or non-detection of the commercial may be caused by this margin of error.
In addition to the above, there arises a further problem that, when a television station advertisement spot of 5 seconds or so is broadcast between a commercial and a program, such spot fails to be detected as it has no characteristic of commercials, although it may be perceived as a commercial by television viewers.